Helmet or head viewing systems have commonly been used for aeronautical applications for several decades. A head viewing system mainly comprises two sub-assemblies.
The first sub-assembly is a helmet or a headset equipped with a viewing system which projects a collimated image, superimposed on the exterior, toward the user's eye or eyes. Helmet is intended to mean a structure for protecting the head, said structure carrying a certain number of phone or viewing or detection devices. Headset is intended to mean a structure carrying a certain number of phone or viewing or detection devices and not necessarily ensuring a protection function for the head. The system according to the invention is equally a helmet or a head support.
The second sub-assembly is a head posture detection system making it possible to pinpoint in space, with respect to a known reference frame, generally tied to an aircraft, the position and the orientation of the helmet or of the headset. The main function of the viewing system is to be able to present, superimposed on the exterior landscape, so-called “conformal” information, that is to say displayed virtually in the exact direction that it would occupy in the exterior landscape. Thus, if the system displays a video image arising from a sensor and comprising a certain number of objects, the objects represented of this image are exactly superimposed with the objects present on the terrain. The same goes for synthetic representations of objects such as runways, targets or direction indications.